蔬菜中敌敌畏的测定VIP专享VIP免费

蔬菜中敌敌畏的测定摘要:基于有机磷农药对过氧化氢有着氧化联苯胺反应的催化作用，本文以敌敌畏为例，用 Triton X －114 为萃取剂，研究了蔬菜表面敌敌畏的含量。在 pH 值为 8.5 的氨缓冲溶液中，过氧化氢溶液与盐酸联苯胺在敌敌畏的催化作用下生成稳定的黄色配合物，经浊点萃取测定敌敌畏的含量。配合物的最大吸收波长为 425 nm，在 0μg 250 μg 范围内吸光值呈良好的线性关系，相关系数为 0.9998，表观摩尔吸光系数 ε 为 5.3 ×104L·mol-1·cm-1，方法检出限为 22.2μg/L，对 5 种蔬菜中敌敌畏的残留量进行了分析，平均回收率为 82.3% ～102%，RSD≤8.9%。关键词:敌敌畏；浊点萃取；蔬菜ABSTRACT:Based on the catalytic effect of organophosphorus pesticides on the reaction of benzidine hydroperoxide, the characteristics of the cloud point extraction system for dichlorvos detection were studied by using Divon X-114 as extractant. In an ammonia buffer solution with a pH of 8.5, hydrogen peroxide and benzidine hydrochloride form a stable yellow complex under the catalysis of dichlorvos, and the content is determined by cloud point extraction. The maximum absorption wavelength of the complex is 425 nm, and the absorbance value is in a good linear relationship in the range of 0 μg 250 μg, the correlation coefficient is 0.999 8, and the apparent molar absorptivity ε is 5.3 × 104 L·mol -1 · cm -1 . The detection limit was 22.2 μg/L. For the analysis of the residual amount of dichlorvos in five kinds of vegetables, the average spiked recovery rate was 82.3% to 102%, and the RSD was ≤8.9%.Keys：Dichlorvos; cloud point extraction; catalytic spectrophotometry; vegetables第1章引言蔬菜中残留的敌敌畏，对于广大人民群众来说都是值得注意的问题，伴随着我国经济的不断发展，我国的是食品安全也频繁出现问题，很多不良商家为了谋取高昂的利润，枉顾国家法律与政策，特别是在使用农药这一块，没有按照规定来操作，导致很多的农产品农药残留量超标甚至严重超标，极...